In general, to test electrical properties of a semiconductor device, a stable electrical connection between the semiconductor device and test equipment (not shown) is essential. A test socket is typically used to connect between a semiconductor and test equipment.
The test socket enables bidirectional exchange of electric signals between a terminal of a semiconductor device that is a device to be tested and a pad of the test equipment. To this end, a test probe such as a pogo pin is used as a contact device in the test socket. The pogo pin with a spring inside may facilitate connection between the semi-conductor device and the test equipment and buffer mechanical shocks generated when the semiconductor device and the test equipment are connected to each other. Accordingly, the pogo pin has been widely used for most test sockets.
FIG. 1 is a cross-sectional view of a test probe used for a test socket, according to a related art. Referring to FIG. 1, a test probe according to a related art includes a barrel 20, an upper pin member 10 having a test probe portion 12 and capable of slidably moving in the barrel 20, a lower pin member 40 formed in a lower end portion of the barrel 20. A compression coil spring 30 is accommodated in the barrel 20 so as to elastically support the upper pin member 10.
When a device to be tested (not shown), such as a microchip, is tested in the above structure, a microchip is placed on top of a test socket and a pressing device (not shown) presses downwardly the microchip so that the microchip contacts a tip of the test probe portion 12 of the upper pin member 10.